Imports github.com/go-acme/lego/certificate github.com/go-acme/lego/registration github.com/go-acme/lego/acme/api github.com/go-acme/lego/certcrypto github.com/go-acme/lego/challenge/resolver Standard library imports io/ioutil net net/http net/url os time crypto/tls crypto/x509 errors fmt